Implantable medical devices (IMDs) for sensing physiological signals and/or delivering automatic therapies are available for a number of medical applications for monitoring and/or treating medical conditions. In order to promote patient comfort, biocompatibility, and enable minimally invasive implantation procedures, in certain situations it may be desirable to reduce the overall size of an IMD and provide smooth, rounded exterior contours of the IMD housing. Reduced-size housings, with smooth contoured shapes, however, can increase manufacturing complexity and/or cost of the IMD.